Lightweight, compact lie flat buggy that fits car seat?!

Thanks for the ideas you guys, its gives me and my wife a really good idea of what we need to get because we're having our first child in less than a month. my wife really wants a diaper bag that's pretty trendy, and obviously we're pretty new to the parenting accessories buying world so we need a little advice. we found this site, www.squidoo.com/best-cool-baby-diaper-bag-for-dad-and-mom and she really likes the jj cole one she found on that site. we're just curious if any of you moms like the jj cole brand and if we should go with a different brand what we should go with? any help would be appreciated!

There's a review here which may be useful. It sounds like the writer got documentation / clearance beforehand. I can't wait to take the YoYo on the plane. The best thing is, its so tiny that you could still take a full size pushchair if you wanted to in the hold!!

It is near impossible but the Babyzen YoYo will do everything but take a car seat. It is one absolutely awesome pushchair. It lies pretty flat for sleeping but its not suitable from birth - only 6 months. The Petite Star Zia (or Zia Evolve if you have a newborn) or Quinny Zapp Xtra are probably the next nearest to your description but they aren't as small. Both take a car seat and both are suitable from birth.The Takeoff officially isn't allowed in an overhead locker but its a fab little pushchair. The Mutsy Spider and TFK Dot could be worth a look too.

The biggest issues really with flying are that it is exceedingly rare to get your pushchair back at the end of your flight. You can almost always take it to the gate with you (except at certain flights at Gatwick where a weight limit has been placed on the pushchair you can take to the gate with you). Believe me, trying to carry a 10-15 month old non walking baby for the distance from the plane, through passport control and on to waiting in baggage reclaim with moving belts and filthy floors and no seats is NO fun at all. If you fly regularly the YoYo would be worth its weight in gold. For a one off flight, I would be looking for something sturdy rather than lightweight to go into a travel bag for the flight. My choice would probably be something like a City Mini that is flat, pretty robust and doesn't have bits that could fall off, get caught or trapped etc.

Not sure it does exist. Quinny zap takes a car seat and fits but is too heavy for your specs. Takeoff buggy fits and is lightweight but doesn't appear to take a car seat. Unless someone else knows of a magic solution you probably need to prioritise your wishlist.

I want it to be lightweight (ideally 5kg ish, but 7 max), compact enough to fit in over head locker on a plane (so not umbrella fold?), lies flat for sleeping, folds in one piece and also can have a car seat attached. I'd also like a shoulder strap